Steel H22 QT+NIT
Finish state
AISI/SAE H22 · UNS T20822
QT+NIT = hardened, tempered and gas-nitrided surface
Nitrided case (~0.1–0.2 mm, 900–1100 HV) on a 45–50 HRC core for extra washout and erosion resistance on hot punches.
Values for the QT+NIT condition
Other H22 tempers and conditions
H22 is listed in 6 conditions; see the grade overview at H22.
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
ANNDefault Annealed | Stock condition for machining dies before hardening; max ~235 HB per ASTM A681. | 470 | 790 | 18 | 212 HB | — |
Hot rolled | Mill condition of forged bar before soft annealing — hard and stressed, normally annealed before use. | 900 | 1,150 | 10 | 37 HRC | 3 % IACS |
Hardened & tempered 44–46 HRC | Pick for hot forging dies and mandrels where thermal-fatigue cracking, not wear, is the failure mode. | 1,250 | 1,470 | 9 | 45 HRC | — |
QT+NITThis page Hardened, tempered and gas-nitrided surface | Nitrided case (~0.1–0.2 mm, 900–1100 HV) on a 45–50 HRC core for extra washout and erosion resistance on hot punches. | 1,380 | 1,620 | 7 | 48 HRC | 3 % IACS |
Hardened & tempered 48–52 HRC | Standard working hardness after ~1200 °C austenitizing and 600–650 °C double temper — best balance of hot hardness and toughness. | 1,450 | 1,720 | 7 | 50 HRC | 28 W/m·K |
Hardened & tempered 53–55 HRC | Use only for short-run hot punches and extrusion mandrels where abrasion dominates and shock loading is low. | 1,620 | 1,930 | 4 | 54 HRC | — |
What is H22 QT+NIT?
H22 QT+NIT is H22 supplied in the QT+NIT condition — nitrided case (~0.1–0.2 mm, 900–1100 HV) on a 45–50 HRC core for extra washout and erosion resistance on hot punches. H22 QT+NIT has a yield strength of 1,380 MPa (200 ksi) and a tensile strength of 1,620 MPa (235 ksi) — stronger than 96% of steel grades. Elongation at break is 7% and the elastic modulus is 207 GPa (30 Msi). H22 QT+NIT has a density of 8.45 g/cm³ (0.305 lb/in³), heavier than 99% of steel grades. It melts at 1,425°C (2,597 °F). ANN is the default condition FabDigit quotes; QT+NIT is available on request or by drawing note.
Advantages
- High service temperature — 600°C (1,112 °F), better than 98% of steel grades
- High strength — 1,380 MPa (200 ksi), better than 96% of steel grades
- Good corrosion resistance — 25/100, better than 92% of steel grades
Limitations
- Difficult to machine — 3/100, worse than 100% of steel grades
- Difficult to weld — 5/100, worse than 100% of steel grades
- Limited formability — 2/100, worse than 100% of steel grades
- Low fracture toughness — 24 MPa·√m (21.8 ksi·√in), worse than 98% of steel grades
- Limited ductility — 7%, worse than 96% of steel grades
H22 QT+NIT properties
Typical room-temperature values for H22 QT+NIT; 22 are specific to this condition. Other listed values are H22 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
H22 QT+NIT has a density of 8.45 g/cm³ (0.305 lb/in³), heavier than 99% of steel grades. It melts at 1,425°C (2,597 °F).
Mechanical16
H22 QT+NIT has a yield strength of 1,380 MPa (200 ksi) and a tensile strength of 1,620 MPa (235 ksi) — stronger than 96% of steel grades. Elongation at break is 7% and the elastic modulus is 207 GPa (30 Msi).
Thermal6
H22 QT+NIT is rated for continuous service to 600°C (1,112 °F). It conducts heat at 29 W/m·K (16.8 BTU/hr·ft·°F), worse than 84% of steel grades. Thermal expansion is 11 µm/m·K (6.11 µin/in·°F).
Electrical3
H22 QT+NIT conducts electricity at 3 % IACS, worse than 91% of steel grades.
Chemical & Environmental3
Corrosion resistance is poor (25/100), better than 92% of steel grades.
Sustainability4
Producing a kilogram of H22 QT+NIT takes about 52 MJ of energy and emits 3.6 kg of CO₂ — more than 94% of steel grades. Typical recycled content is 45%.
Manufacturability8
H22 QT+NIT's machinability is not recommended (3/100, worse than 100% of steel grades); weldability not recommended (5/100); formability not recommended (2/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with H22 QT+NIT
Is H22 easy to machine?
Machine only in the annealed condition with rigid setups, positive-rake carbide or coated carbide at low speed; the coarse tungsten carbides are abrasive, and above ~45 HRC switch to grinding or EDM (stress-relieve/temper after EDM).
Can H22 be welded?
Repair-weld with matched W-alloy hot-work filler after preheating the whole tool to 350–450 °C, weld hot, cool slowly and re-temper 20–30 °C below the last tempering temperature.
Can H22 be formed, bent or molded?
Hot work only: forge 1050–1150 °C, stop above 900 °C, cool slowly in furnace or ash, then soft anneal 850–900 °C at ≤20 °C/h to ≤235 HB; harden 1150–1200 °C, air or oil quench, double temper 600–650 °C.
What surface finishes work on H22?
No anodizing; use gas nitriding, oxidizing/black finish or PVD (CrN, AlTiN) for wash resistance, and keep oiled or VCI-wrapped since the low-Cr matrix rusts quickly.
H22 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| C | 0.3 – 0.4 | 0.35 |
| Mn | 0.15 – 0.4 | 0.3 |
| Si | 0.15 – 0.4 | 0.3 |
| Crlower Cr than H21 | 1.75 – 3.75 | 2.5 |
| Wprimary hot-hardness element | 10 – 11.75 | 11 |
| V | 0.25 – 0.5 | 0.35 |
| Moresidual, not intentionally added | ≤ 0.3 | — |
| Niresidual | ≤ 0.3 | — |
| Curesidual | ≤ 0.25 | — |
| P | ≤ 0.03 | — |
| S | ≤ 0.03 | — |
| Fe | balance | — |
H22 QT+NIT — frequently asked
What is H22 QT+NIT used for?
H22 QT+NIT is typically used for hot punches, hot shear blades, extrusion tooling and hot forming dies. In short: high-tungsten H21 variant; 500 °C service capability; low corrosion resistance.
What is the yield strength of H22 QT+NIT?
H22 QT+NIT has a typical yield strength of 1,380 MPa (200 ksi) and a tensile strength of 1,620 MPa (235 ksi) — stronger than 96% of steel grades. Strength varies by condition: see the 6 listed tempers.
Is H22 QT+NIT easy to machine?
Not especially — machinability is rated not recommended (3/100, worse than 100% of steel grades). Machine only in the annealed condition with rigid setups, positive-rake carbide or coated carbide at low speed; the coarse tungsten carbides are abrasive, and above ~45 HRC switch to grinding or EDM (stress-relieve/temper after EDM).
Can H22 QT+NIT be welded?
Not readily — weldability is rated not recommended (5/100). Repair-weld with matched W-alloy hot-work filler after preheating the whole tool to 350–450 °C, weld hot, cool slowly and re-temper 20–30 °C below the last tempering temperature.
What surface finishes work on H22 QT+NIT?
No anodizing; use gas nitriding, oxidizing/black finish or PVD (CrN, AlTiN) for wash resistance, and keep oiled or VCI-wrapped since the low-Cr matrix rusts quickly.
Can H22 QT+NIT be formed, bent or molded?
Hot work only: forge 1050–1150 °C, stop above 900 °C, cool slowly in furnace or ash, then soft anneal 850–900 °C at ≤20 °C/h to ≤235 HB; harden 1150–1200 °C, air or oil quench, double temper 600–650 °C.
What is the maximum service temperature of H22 QT+NIT?
H22 QT+NIT is rated for continuous use to about 600°C (1,112 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between H22-ANN and H22-QT54?
ANN is the default condition — stock condition for machining dies before hardening; max ~235 HB per ASTM A681. QT54: use only for short-run hot punches and extrusion mandrels where abrasion dominates and shock loading is low. Yield strength is 470 MPa in ANN versus 1,620 MPa in QT54.
Sources
- ASTM A681 — Standard Specification for Tool Steels, Alloy — ASTM International (2015)
- ASM Handbook Vol.1: Properties and Selection — Irons, Steels, and High-Performance Alloys (Hot-Work Tool Steels) — ASM International (1990)
- ASM Handbook Vol.4: Heat Treating (Tool Steel Heat Treatment) — ASM International (1991)
- ASM Handbook Vol.16: Machining (Machinability of Tool Steels) — ASM International (1989)
- SAE J438 / UNS T20822 tool steel designations — SAE International (2019)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.